Portal:History of science/Selected anniversaries/April

1557 - Death of Petrus Apianus, German mathematician (b. 1495)
1652 - Birth of Michel Rolle, French mathematician (d. 1719)
1719 - Death of Philippe de La Hire, French mathematician and historian (b. 1640)
1774 - Birth of Jean-Baptiste Biot, French physicist (d. 1862)
1825 - Death of Johann Friedrich Pfaff, German mathemattician (b. 1765)
1851 - Birth of Charles Barrois, French geologist (d. 1939)
1882 - Birth of Percy Williams Bridgman, American physicist, Nobel laureate (d. 1961)
1889 - Birth of Paul Karrer, Swiss chemist, Nobel laureate (d. 1971)
1915 - Birth of Garrett Hardin, American ecologist (d. 2003)
1951 - Birth of Michael Hartley Freedman, American mathematician
1965 - Death of Edward Victor Appleton, English physicist, Nobel Prize laureate (b. 1892)
1980 - Death of Alexander Oparin, Russian biochemist (b. 1894)
1994 - The first discoveries of extrasolar planets are announced by astronomer Aleksander Wolszczan

April 22:

1500 – Portuguese navigator Pedro Álvares Cabral becomes the first European to sight Brazil

1692 – birth of James Stirling, Scottish mathematician (d. 1770)

1758 – death of Antoine de Jussieu, French naturalist (b. 1686)

1891 – birth of Harold Jeffreys, English astronomer (d. 1989)

1904 – birth of J. Robert Oppenheimer, American physicist (d. 1967)

1909 – birth of Rita Levi-Montalcini, Italian neurologist, Nobel laureate

1910 – birth of Norman Steenrod, American mathematician (d. 1971)

1919 – birth of Donald J. Cram, American chemist, Nobel laureate (d. 2001)

1922 – birth of Wolf V. Vishniac, American microbiologist (d. 1973)

1929 – birth of Michael Atiyah, mathematician

1945 – death of Wilhelm Cauer, German mathematician (b. 1900)

1951 – death of Horace Donisthorpe, British entomologist (b. 1870)

1970 – first Earth Day celebrated

1980 – death of Fritz Strassmann, German physicist (b. 1902)

2005 – death of Philip Morrison, American physicist (b. 1915)

April 23:

1628 - Birth of Johann van Waveren Hudde, Dutch mathematician (d. 1704)

1635 - First public school in the United States, Boston Latin School, is founded in Boston, Massachusetts

1746 - Birth of Félix Vicq-d'Azyr, French physician and anatomist (d. 1794)

1792 - Birth of John Thomas Romney Robinson, Irish astronomer and physicist (d. 1882)

1858 - Birth of Max Planck, German physicist, Nobel Prize laureate (d. 1947)

1867 - William Lincoln patents the zoetrope, a machine which shows animated pictures by mounting a strip of drawings in a wheel

1867 - Birth of Johannes Andreas Grib Fibiger, Danish scientist, recipient of the Nobel Prize in Physiology or Medicine (d. 1928)

1901 - Birth of E.B. Ford, British ecological geneticist (d. 1988)

April 24:

1620 - Birth of John Graunt, English statistician and founder of the science of demography (d. 1674)

1656 - Death of Thomas Fincke, Danish mathematician and physicist (b. 1561)

1899 - Birth of Oscar Zariski, Russian-born mathematician (d. 1986)

1916 - Ernest Shackleton and five men of the Imperial Trans-Antarctic Expedition launch a lifeboat from uninhabited Elephant Island in the Southern Ocean to organise a rescue for ice-trapped ship Endurance

1947 - Birth of Roger D. Kornberg, American chemist, Nobel-prized

1960 - Death of Max von Laue, German physicist, Nobel Prize laureate (b. 1879)

1964 - Death of Gerhard Domagk, German bacteriologist, recipient of the Nobel Prize in Physiology or Medicine (declined) (b. 1895)

1990 - STS-31: The Hubble Space Telescope is launched by the Space Shuttle Discovery

April 25:

1710 - Birth of James Ferguson, Scottish astronomer (d. 1776)

1744 - Death of Anders Celsius, Swedish astronomer (b. 1701)

1770 - Death of Jean-Antoine Nollet, French abbot and physicist (b. 1700)

1840 - Death of Siméon-Denis Poisson, French mathematician (b. 1781)

1849 - Birth of Felix Klein, German mathematician (d. 1925)

1874 - Birth of Guglielmo Marconi, Italian inventor, recipient of the Nobel Prize in Physics (d. 1937)

1900 - Birth of Wolfgang Ernst Pauli, Austrian-born physicist, Nobel Prize laureate (d. 1958)

1903 - Birth of Andrey Nikolayevich Kolmogorov, Russian mathematician (d. 1987)

1918 - Birth of Gerard Henri de Vaucouleurs, French astronomer (d. 1995)

1931 - Birth of Felix Berezin, Russian mathematician (d. 1980)

1953 - Francis Crick and James D. Watson publish Molecular structure of nucleic acids: a structure for deoxyribose nucleic acid describing the double helix structure of DNA.

1959 - The St. Lawrence Seaway, linking the North American Great Lakes and the Atlantic Ocean, officially opens to shipping.

1961 - Robert Noyce is granted a patent for an integrated circuit

2000 - Death of Lucien le Cam, French mathematician (b. 1924)

April 26:

1774 - Birth of Christian Leopold von Buch, German geologist (d. 1853)

1785 - Birth of John James Audubon, French-American naturalist and illustrator (d. 1851)

1879 - Birth of Owen Willans Richardson, British physicist, Nobel Prize laureate (d. 1959)

1900 - Birth of Charles Richter, American geophysicist (d. 1985)

1920 - Death of Srinivasa Ramanujan, Indian mathematician (b. 1887)

1932 - Birth of Michael Smith, English-born chemist, Nobel laureate (d. 2000)

1933 - Birth of Arno Allan Penzias, German-born physicist, Nobel laureate

1940 - Death of Carl Bosch, German chemist, Nobel laureate (b. 1874)

1951 - Death of Arnold Sommerfeld, German physicist (b. 1868)

1986 - In Ukraine, a nuclear reactor accident occurs at the Chernobyl Nuclear Power Plant, creating the world's worst nuclear disaster

1994 - Physicists announce first evidence of the top quark subatomic particle

April 27:

1748 - Birth of Adamantios Korais, Greek humanist scholar (d. 1833)

1755 - Birth of Marc-Antoine Parseval, French mathematician (d. 1836)

1913 - Birth of Philip Hauge Abelson, American physicist (d. 2004)

1927 - Birth of Karl Alexander Müller, Swiss physicist, Nobel Prize laureate

1932 - Birth of Gian-Carlo Rota, Italian-born mathematician and philosopher (d. 1999)

1936 - Death of Karl Pearson, English statistician (b. 1857)

1967 - Expo 67 officially opens in Montreal, Canada with a large opening ceremony broadcast around the world. It opens to the public the next day

1981 - Xerox PARC introduces the computer mouse

1992 - Death of Gerard K. O'Neill, American physicist (b. 1927)

2002 - The last successful telemetry from the NASA space probe Pioneer 10

April 28:

1765 - Birth of Sylvestre François Lacroix, French mathematician (b. 1834)

1868 - Birth of Georgy Voronoy, Russian mathematician (d. 1908)

1902 - Using the ISO 8601 standard Year Zero definition for the Gregorian calendar preceded by the Julian calendar, the one billionth minute since the start of January 1, Year Zero occurs at 10:40 AM on this date

1906 - Birth of Kurt Gödel, Austrian mathematician (d. 1978)

1932 - A vaccine for yellow fever is announced for use on humans

1941 - Birth of K. Barry Sharpless, American chemist, Nobel laureate

1946 - Death of Louis Bachelier, French mathematician (b. 1870)

1997 - The 1993 Chemical Weapons Convention goes into effect, with Russia, Iraq and North Korea notable nations who have not ratified the treaty

1999 - Death of Arthur Leonard Schawlow, American physicist, Nobel laureate (b. 1921)

2005 - The Patent Law Treaty goes into effect

April 29:

1768 - Death of Georg Brandt, Swedish chemist and mineralogist (b. 1694)

1770 - James Cook arrives at and names Botany Bay, Australia

1793 - Death of John Michell, English scientist (b. 1724)

1798 - Death of Nikolaus Poda von Neuhaus, German entomologist (b. 1723)

1854 - Birth of Henri Poincaré, French mathematician and physicist (d. 1912)

1893 - Birth of Harold Urey, Nobel Prize laureate (d. 1981)

1916 - Death of Jørgen Pedersen Gram, Danish mathematician (b. 1850)

1966 - Death of William Eccles, English physicist and radio pioneer (b. 1875)

2008 - Death of Albert Hofmann, Swiss chemist, known as the first to synthesize LSD (b. 1906)

April 30:

1006 - Supernova SN 1006, the brightest supernova in recorded history, appears in the constellation Lupus

1483 - Orbital calculations suggest that on this day, Pluto moved inside Neptune's orbit until July 23, 1503.

1492 - Spain gives Christopher Columbus his commission of exploration

1696 - Robert Plot, British naturalist (b. 1640)

1723 - Birth of Mathurin Jacques Brisson, French naturalist (d. 1806)

1777 - Birth of Carl Friedrich Gauss, German mathematician (d. 1855)

1829 - Birth of Ferdinand von Hochstetter, Austrian geologist (d. 1884)

1875 - Jean-Frédéric Waldeck, French explorer, lithographer, and cartographer (b. 1766)

1876 - Birth of Orso Mario Corbino, Italian physicist (d. 1937)

1916 - Birth of Claude Shannon, American engineer and mathematician (d. 2001)